Battle of Rancagua: Spanish Royalists troops under Mariano Osorio defeats rebel Chilean forces of Bernardo O'Higgins and José Miguel Carrera.

The Battle of Rancagua, also known in Chile as the Disaster of Rancagua, occurred on October 1, 1814, to October 2, 1814, when the Spanish Army under the command of Mariano Osorio defeated the rebel Chilean forces led by Bernardo O’Higgins. This put an end to the Chilean Patria Vieja and it was the decisive step of the Spanish military Reconquest of Chile.